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Commit 9ace903d authored by Christian Ehrhardt's avatar Christian Ehrhardt Committed by Avi Kivity
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KVM: s390: infrastructure to kick vcpus out of guest state 



To ensure vcpu's come out of guest context in certain cases this patch adds a
s390 specific way to kick them out of guest context. Currently it kicks them
out to rerun the vcpu_run path in the s390 code, but the mechanism itself is
expandable and with a new flag we could also add e.g. kicks to userspace etc.

Signed-off-by: default avatarChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 3032b925

arch/s390/include/asm/kvm_host.h

+3 −2
Original line number Diff line number Diff line
@@ -182,8 +182,9 @@ struct kvm_s390_interrupt_info { 
};



/* for local_interrupt.action_flags */

#define ACTION_STORE_ON_STOP 1

#define ACTION_STOP_ON_STOP  2

#define ACTION_STORE_ON_STOP		(1<<0)

#define ACTION_STOP_ON_STOP		(1<<1)

#define ACTION_RELOADVCPU_ON_STOP	(1<<2)



struct kvm_s390_local_interrupt {

	spinlock_t lock;

arch/s390/kvm/intercept.c

+9 −3
Original line number Diff line number Diff line
@@ -128,7 +128,7 @@ static int handle_noop(struct kvm_vcpu *vcpu) 


static int handle_stop(struct kvm_vcpu *vcpu)

{

	int rc;

	int rc = 0;



	vcpu->stat.exit_stop_request++;

	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
@@ -141,12 +141,18 @@ static int handle_stop(struct kvm_vcpu *vcpu) 
			rc = -ENOTSUPP;

	}



	if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {

		vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;

		rc = SIE_INTERCEPT_RERUNVCPU;

		vcpu->run->exit_reason = KVM_EXIT_INTR;

	}



	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {

		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;

		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");

		rc = -ENOTSUPP;

	} else

		rc = 0;

	}



	spin_unlock_bh(&vcpu->arch.local_int.lock);

	return rc;

}

arch/s390/kvm/kvm-s390.c

+5 −0
Original line number Diff line number Diff line
@@ -490,6 +490,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 


	vcpu_load(vcpu);



rerun_vcpu:

	/* verify, that memory has been registered */

	if (!vcpu->kvm->arch.guest_memsize) {

		vcpu_put(vcpu);
@@ -509,6 +510,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		vcpu->arch.sie_block->gpsw.addr = kvm_run->s390_sieic.addr;

		break;

	case KVM_EXIT_UNKNOWN:

	case KVM_EXIT_INTR:

	case KVM_EXIT_S390_RESET:

		break;

	default:
@@ -522,6 +524,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		rc = kvm_handle_sie_intercept(vcpu);

	} while (!signal_pending(current) && !rc);



	if (rc == SIE_INTERCEPT_RERUNVCPU)

		goto rerun_vcpu;



	if (signal_pending(current) && !rc)

		rc = -EINTR;

arch/s390/kvm/kvm-s390.h

+3 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 


typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu);



/* negativ values are error codes, positive values for internal conditions */

#define SIE_INTERCEPT_RERUNVCPU		(1<<0)

int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu);



#define VM_EVENT(d_kvm, d_loglevel, d_string, d_args...)\
@@ -50,6 +52,7 @@ int kvm_s390_inject_vm(struct kvm *kvm, 
int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,

		struct kvm_s390_interrupt *s390int);

int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code);

int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action);



/* implemented in priv.c */

int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);

arch/s390/kvm/sigp.c

+34 −22
Original line number Diff line number Diff line 
/*

 * sigp.c - handlinge interprocessor communication

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License (version 2 only)
@@ -9,6 +9,7 @@ 
 *

 *    Author(s): Carsten Otte <cotte@de.ibm.com>

 *               Christian Borntraeger <borntraeger@de.ibm.com>

 *               Christian Ehrhardt <ehrhardt@de.ibm.com>

 */



#include <linux/kvm.h>
@@ -107,46 +108,57 @@ unlock: 
	return rc;

}



static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int store)

static int __inject_sigp_stop(struct kvm_s390_local_interrupt *li, int action)

{

	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;

	struct kvm_s390_local_interrupt *li;

	struct kvm_s390_interrupt_info *inti;

	int rc;



	if (cpu_addr >= KVM_MAX_VCPUS)

		return 3; /* not operational */



	inti = kzalloc(sizeof(*inti), GFP_KERNEL);

	if (!inti)

		return -ENOMEM;



	inti->type = KVM_S390_SIGP_STOP;



	spin_lock(&fi->lock);

	li = fi->local_int[cpu_addr];

	if (li == NULL) {

		rc = 3; /* not operational */

		kfree(inti);

		goto unlock;

	}

	spin_lock_bh(&li->lock);

	list_add_tail(&inti->list, &li->list);

	atomic_set(&li->active, 1);

	atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);

	if (store)

		li->action_bits |= ACTION_STORE_ON_STOP;

	li->action_bits |= ACTION_STOP_ON_STOP;

	li->action_bits |= action;

	if (waitqueue_active(&li->wq))

		wake_up_interruptible(&li->wq);

	spin_unlock_bh(&li->lock);

	rc = 0; /* order accepted */



	return 0; /* order accepted */

}



static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int action)

{

	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;

	struct kvm_s390_local_interrupt *li;

	int rc;



	if (cpu_addr >= KVM_MAX_VCPUS)

		return 3; /* not operational */



	spin_lock(&fi->lock);

	li = fi->local_int[cpu_addr];

	if (li == NULL) {

		rc = 3; /* not operational */

		goto unlock;

	}



	rc = __inject_sigp_stop(li, action);



unlock:

	spin_unlock(&fi->lock);

	VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);

	return rc;

}



int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action)

{

	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;

	return __inject_sigp_stop(li, action);

}



static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)

{

	int rc;
@@ -262,11 +274,11 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) 
		break;

	case SIGP_STOP:

		vcpu->stat.instruction_sigp_stop++;

		rc = __sigp_stop(vcpu, cpu_addr, 0);

		rc = __sigp_stop(vcpu, cpu_addr, ACTION_STOP_ON_STOP);

		break;

	case SIGP_STOP_STORE_STATUS:

		vcpu->stat.instruction_sigp_stop++;

		rc = __sigp_stop(vcpu, cpu_addr, 1);

		rc = __sigp_stop(vcpu, cpu_addr, ACTION_STORE_ON_STOP);

		break;

	case SIGP_SET_ARCH:

		vcpu->stat.instruction_sigp_arch++;